Due to the increased use of non-conducting material combinations in the vehicle body, all the way to the complete carbon-fiber-reinforced polymers (CFRP) body (such as monocoque) and a wide variety of joining techniques such as adhesive bonding, riveting, welding and the like, the ground return current from a consumer to a battery, which is typically conducted into the body via grounding combs, will be undefined or non-directional in the future. This undefined ground return current may create an electromagnetic field, which can decisively influence, or possibly even harm, vehicle passengers and on-board electronics. As a result, the previously customary electric ground return via the vehicle body is drastically impaired or practically impossible.
This problem may be solved by a ground return when a greater number of stranded conductors is installed. However, this increases the weight of the onboard electrical system or of the wiring harness.
The use of flat conductors for ground return may allow the installation space and the conductor weight to be reduced. The flat conductor is installed along the floor pan contour from a rear compartment to an engine compartment. A flat conductor structure as a central electrical supply unit and ground return additionally eliminates the development of an electric magnetic field independently of the body materials. This flat conductor system in the vehicle moreover achieves improved stability of the on-board electrical system.
Due to the flat design, the individual flat conductors, or flat conductors having a multi-layer composition (multi-rail), have contact elements or contact systems protruding on the side and/or end face so as not to impair adjoining flat conductors. The contact elements or contact systems lead via stranded conductors to respective consumers, such as electrical and/or electronic circuits, such as of an electronic system, a sensor system, an actuator system and the like.
The flat conductors can be protected with respect to the contacted stranded conductors, which can be achieved, for example, by a fusible cutout between the flat conductor and the stranded conductor. A fusible cutout implemented by a cross-sectional (area) reduction can result in drastic temperature increases locally due to a locally increased current density. Avoiding such local temperature concentrations outside of a safety incident has been technologically complex and/or cost-intensive until now.